MediaRouterAction: Only observe Media Routes when there is a local route.

chrome/browser/media/router/mock_media_router.h

Index: chrome/browser/media/router/mock_media_router.h
diff --git a/chrome/browser/media/router/mock_media_router.h b/chrome/browser/media/router/mock_media_router.h
index 6c1a9e99f2bae3adc67d61549fdd0e33b4753c0f..e70db42ce1998d328e40aa307f82c374747fb140 100644
--- a/chrome/browser/media/router/mock_media_router.h
+++ b/chrome/browser/media/router/mock_media_router.h
@@ -54,6 +54,7 @@ class MockMediaRouter : public MediaRouter {
   MOCK_METHOD1(ClearIssue, void(const Issue::Id& issue_id));
   MOCK_METHOD1(OnPresentationSessionDetached,
                void(const MediaRoute::Id& route_id));
+  MOCK_CONST_METHOD0(HasLocalRoute, bool());
   MOCK_METHOD1(RegisterIssuesObserver, void(IssuesObserver* observer));
   MOCK_METHOD1(UnregisterIssuesObserver, void(IssuesObserver* observer));
   MOCK_METHOD1(RegisterMediaSinksObserver, bool(MediaSinksObserver* observer));
@@ -67,6 +68,10 @@ class MockMediaRouter : public MediaRouter {
                void(PresentationSessionMessagesObserver* observer));
   MOCK_METHOD1(UnregisterPresentationSessionMessagesObserver,
                void(PresentationSessionMessagesObserver* observer));
+  MOCK_METHOD1(RegisterLocalMediaRoutesObserver,
+               void(LocalMediaRoutesObserver* observer));
+  MOCK_METHOD1(UnregisterLocalMediaRoutesObserver,
+               void(LocalMediaRoutesObserver* observer));
 };
 
 }  // namespace media_router